This application claims the benefit of Korean Patent Application No. 2001-16868 filed on Mar. 30, 2001, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a hard disk drive, and more particularly, to an actuator latch used with a hard disk drive which fixes an actuator of the hard disk drive in a parking zone when the actuator does not operate.
2. Description of the Related Art
In general, a hard disk as one of auxiliary memory devices in a computer records data on a hard disk or reproduces data from the hard disk. An actuator having a magnet head functioning as an electromagnet is installed in the hard disk drive.
When the hard disk drive is actuated, the actuator rotates so that the magnetic head moves from the parking zone to a data zone. The magnetic head of the actuator writes data on the hard disk or reads data that is stored magnetically on the hard disk.
When the electric power is turned off to end the use of a computer, a driving voltage to a spindle motor also stops so that the speed of the hard disk rotated by the spindle motor gradually decreases. At this point, the magnetic head in the state of flying above the hard disk by the flow of air descends onto the surface of the hard disk. However, when the magnetic head lands on the surface of the data zone of the hard disk, the magnetic surface of the hard disk or data recorded on the hard disk may be damaged. To prevent the above problem, a parking zone is provided on the surface of the hard disk. Here, the parking zone is a portion of the surface of the hard disk where no data is recorded. The magnetic head is moved to the parking zone by a program before it lands on the surface of the hard disk.
When external impacts or vibrations are applied to the hard disk drive in an operation ready mode, the magnetic head, staying in the parking zone, is forced to be moved to a data zone while contacting the hard disk. The magnetic head intruding on the data zone damages the surface of the hard disk as well as the data stored in the hard disk by contacting the surface of the hard disk.
Thus, to prevent the above problem, an actuator latch for firmly fixing the magnetic head during external impacts or vibrations by supporting the magnetic head in the parking zone with a particular force, is used.
FIG. 1 shows a conventional hard disk drive that is disclosed in U.S. Pat. No. 5,636,090. Referring to FIG. 1, the conventional hard disk drive 100 includes a hard disk 120 rotatably installed at a housing 110 and having a data zone 121 where data is recorded and a parking zone 122 where no data is recorded, an actuator 130 transferring the magnetic head 131 that reads and writes information with respect to the hard disk 120 to a desired track position of the hard disk 120, and a latch device 180 preventing the actuator 130 positioned in the parking zone 122 from escaping therefrom.
The magnetic head 131 is installed at one end of the actuator 130, and a bobbin portion 134, around which a coil 133 is wound to generate a magnetic field, is installed at the other end of the actuator 130. The actuator 130 is installed to be capable of pivoting around a pivot shaft 136 installed at the housing 110. The bobbin portion 134 moves the actuator 130 to a desired track of the hard disk 120 by an electromagnetic force generated between a stator 140 and a yoke 150 installed at the housing 110.
The latch device 180 is installed to be capable of pivoting around a rotation shaft 161 installed at the housing 110, and includes a locking member 160 and a spring 170. In the locking member 160, a latch hole 163 is provided at one end of the locking member 160 to latch a finger portion 139 that is provided at one side of the bobbin portion 134 and an inertia member 162 is provided at the other end thereof. The spring 170 is connected to the locking member 160 and provides an elastic force.
In the above structure, when the actuator 130 moves above the hard disk 120 and/or there is no external impact, including rotational impact, the finger portion 139 is elastically biased by the spring 170. Thus, since the actuator 130 is not firmly held by the latch hole 163, the actuator 130 moves to the data zone 121 from the parking zone 122 and reads or records data with respect to the hard disk 120.
When the actuator 130 is positioned in the parking zone 122 and the hard disk 120 receives a clockwise rotational impact externally with respect to the drawing, the actuator 130 rotates counterclockwise due to a rotational inertial force. Also, the locking member 160, reacting more sensitively than the actuator 130, rotates counterclockwise so that the finger portion 139 is inserted in the latch hold 163 and firmly held therein. Thus, the actuator 130 is prevented from escaping from the parking zone 122.
However, when a counterclockwise rotational impact with respect to the drawing is applied to the hard disk 120, the actuator 130 rotates clockwise due to a rotational inertial force, and the locking member 160 also rotates clockwise. Thus, the finger portion 139 is not firmly held by the latch hole 163.
FIG. 2 shows a conventional load-unload hard disk drive having a ramp. Referring to FIG. 2, the hard disk drive 200 includes a hard disk 220, an actuator 230, and an actuator latch 280. The hard disk 220 is divided into a data zone 222 where data is recorded and a parking zone 221 where no data is recorded.
The actuator 230 is installed to be capable of pivoting at a pivot shaft 235, which is installed at a housing 210. A magnetic head 231 is provided at one end of the actuator 230 and a bobbin portion 234, around which a coil 233 is wound, is provided at the other end thereof. The bobbin portion 234 generates an electromagnetic force between the bobbin portion 234 and a stator 250 installed at the housing 210 so that the actuator 230 can be positioned at a desired track of the hard disk 220. A finger portion 237, to be caught by a hook portion 261 of a locking member 260, is provided at one side of the bobbin portion 234. A magnetic portion 236, corresponding to a magnet match 240 installed at the stator 250, is provided at the other side of the bobbin portion 234.
A ramp 290 is installed at the housing 210 close to the hard disk 220. The magnetic head 231 is accommodated on the ramp 290 when the actuator 230 is parked.
The actuator latch 280 includes the locking member 260 having the hook portion 261 at one end thereof and a spring 270 connected at the other end thereof and is installed to be capable of pivoting by being inserted in a rotation shaft 263 installed at the housing 210. The spring 270 provides an elastic force on the locking member 260, and the finger portion 237 is provided at the bobbin portion 234 to engage with the hook portion 261.
In the above structure, when there is no external impact, or in a normal operation, the hook portion 263 of the actuator latch 280 does not hold the finger portion 237. Here, the actuator 230, overcoming a force between the magnet latch 240 and the magnet portion 236, moves over the data zone 222 of the hard disk 220 to record data or reproduce recorded data.
When there is a relatively weak external impact with respect to a force acting between the magnet latch 240 and the magnet portion 236, the actuator 230 is prevented from escaping from the parking zone 221 by the force acting between the magnet latch 240 and the magnet portion 236. However, when there is a relatively strong clockwise external rotational impact with respect to the force acting between the magnet latch 240 and the magnet portion 236, a clockwise rotational impact with respect to the drawing applies to the hard disk 220. Here, the actuator 230 rotates counterclockwise and may escape from the parking zone 221. Also, the locking member 260 rotates counterclockwise by a rotational inertial force and the hook portion 261 is engaged with the finger portion 237. Thus, the actuator 230 is prevented from escaping from the parking zone 221.
When the external impact disappears, the locking member 260 returns to its original position by an elastic restoring force and the finger portion 237 is released from being held by the hook portion 261.
In the above structure, when the hard disk drive 200 receives a relatively strong clockwise external rotational impact, the actuator 230 receives a counterclockwise rotational inertial force. However, the actuator latch 280 receives a counterclockwise rotational inertial force, and reacts more sensitively than the actuator 230 to the force. Thus, the actuator latch 280 firmly holds the actuator 230 so that the actuator 230 does not escape from the parking zone 221.
However, when the hard disk drive 200 receives a relatively strong counterclockwise rotation impact, the actuator 230, receiving a clockwise rotational inertial force, does not escape from the parking zone 221. Nevertheless, the actuator 230, receiving a counterclockwise rotational force by a repulsive force between the actuator 230 and a stopper 275 installed to limit a range of movement of the actuator 230, may escape from the parking zone 221. Here, since the actuator latch 280 does not firmly hold the actuator 230, the magnetic head 231 of the actuator 230 intrudes the data zone 222, making contact therewith instead of flying over the hard disk 220, so that the surface of the hard disk 220 is physically damaged and, accordingly, data thereon is also damaged.
Accordingly, it is an object of the present invention to provide an actuator latch for a hard disk drive having an improved structure so that the actuator is prevented from escaping from the parking zone regardless of the direction of a rotational impact applied externally.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and other objects of the present invention are achieved by providing an actuator latch for a hard disk drive that locks an actuator so that it does not pivot when a magnetic head installed at the actuator is positioned in a parking zone of a hard disk, the actuator latch comprising a hooked portion provided at one side of the actuator and having first and second hook steps disposed to face each other, a locking member having a hook portion which is coupled to the hooked portion as the actuator moves to the parking zone, the hook portion coupled to the hooked portion being interfered with the first hook step when the actuator rotates clockwise and with the second hook step when the actuator rotates counterclockwise, and an elastic member elastically supporting the locking member to be capable of rotating and providing a restoring force to the locking member with respect to both clockwise and counterclockwise rotations of the locking member.
The above and other objects of the present invention may also be achieved by providing an actuator latch for a hard disk drive that locks an actuator so that it does not pivot when a magnetic head installed at the actuator is positioned in a parking zone of a hard disk, the actuator latch comprising a hook portion provided at one side of the actuator and having first and second hook portions, a locking member having a hooked portion which is coupled to the hook portion as the actuator moves to the parking zone, the hooked portion coupled to the hook portion being interfered with the first hook portion when the actuator rotate clockwise and with the second hook step when the actuator rotates counterclockwise, and an elastic member elastically supporting the locking member to be capable of rotating and proving a restoring force to the locking member with respect to both clockwise and counterclockwise rotations of the locking member.